MOJAVE DESERT, California (CNN) -- The prototype for a
wingless "space lifeboat" enjoyed a successful free flight Thursday in the most important
test it has undergone to date.

NASA tucked the wingless X-38 aircraft under the wing of the
nation's oldest operating B-52 bomber for its first-ever drop
test over the Mojave Desert. The Air Force bomber carried it
into position, then let it go at an altitude of 23,000 feet
(6,977 meters) for a test flight that lasted only a couple of
minutes.

The X-38 is a pilotless craft designed to become the escape
vehicle for the future international space station.

"We're concerned about scenarios on the space station where
someone is injured or we have damage to the space station or
there's a problem with the orbiter and we need to bring the
crew home," said John Muratore, the X-38 mission director.

The X-38 is only one-sixteenth the size of the vehicle that
will be docked at the space station in the year 2003; the
full-size model will hold seven passengers, none of whom will
need to be a pilot, since the escape vehicle will be
controlled from Earth.

The X-38 is built to glide through the sky on lift generated
by its aerodynamic shape before deploying a huge controllable
parachute, or parafoil. The aircraft has no landing gear; it
sets down on skids.

"The parafoil just gives you a lot more capability to land in
almost a dozen places around the Earth," said project manager
Bob Baron. "At Kennedy Space Center, or Edwards Air Force
Base, or the ocean. You can do a lot of things with it."

While the first drop test of the X-38 got near-perfect marks
from scientists in charge of the project, it was not
flawless. Observers held their breath when the parafoil
became twisted, and a tear developed. However, mission
controllers were able to correct the problem during the
spacecraft's descent and it landed exactly as intended.

Now, Muratore said, his team must figure out what went wrong
and correct it.

"What we've got to find is, did the parafoil twist around the
vehicle, or did the vehicle twist around the parafoil?"
Muratore said. "We're going to have to look at the data very
carefully and make sure we're putting the fix in the right
place."

This test was the first of some 30 drop tests the X-38 will
undergo. One of them, scheduled for the year 2000, will test
the entire reentry process when the space shuttle deploys the
craft from space.